The invention relates to a circuit board fault isolation technique and more particularly, to the use of the user interface display screen to display communications between selected boards.
It is important to the maintenance of complex electronic equipment such as reproduction machines to reduce the service cells and time spent in monitoring and maintaining the machine operation, in particular, reducing the cost of maintenance and service. Often diagnostic procedures and trouble shooting codes for a particular machine are totally unique to that machine, and the Service Representative must learn each machine's diagnostic procedures and codes separately. It would be desirable, therefore, to provide standardized diagnostic procedures and codes for use in many machines which the Service Representative can use to correct malfunctions and maintain operation without the need for extensive retraining.
Reproduction machines comprise several interrelated subsystems control boards such as the paper path station, the exposure/scan station, the xerographic station. Checking the operation of the machine, it is often necessary for the Service Representative to isolate on one of the stations to the exclusion of the others. In doing so, the Service Representative is aided by status and maintenance codes displayed on a machine control panel to assist him or her in proper diagnosis and correction of machine malfunction. The Service Representative often used extensive fault trees, charts and trouble shooting procedures to interpret the various codes into corrective procedures. It would be desirable, therefore, to eliminate the need for resort to extensive trouble shooting procedures during machine diagnostics, and it would be desirable to provide a diagnostic system in which communications between boards are visually related and are displayed in a predetermined manner.
On many occasions, a service representative using the machine display screen to assist in machine diagnosis can be frustrated in trouble shooting if the screen itself is malfunctioning. In addition, even if the screen display is operable, a service representative often spends excessive time in pinpointing the source of faulty transmissions between control boards. It would be desirable, therefore, to provide an easy and quick method of isolating faults to a particular control board.
Prior art diagnostic procedures on providing fault information in machines are well known. For example, U.S. Pat. Nos. 4,035,072 and 4,156,133 teach various diagnostic techniques. None of the prior art systems, however, heed the difficulty of adapting to a malfunction of the screen itself as well as a rapid mechanism for isolating faults.
It is an object of the present invention, therefore, to provide a new and improved technique to simply and quickly isolate faults between control boards. It is still another object of the present invention to be able to isolate a malfunction to the board controlling the screen display. It is still another object of the present invention to be able to visually validate communication between selected control boards. Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.